21312123111023 has 8 divisors (see below), whose sum is σ = 21334780327968. Its totient is φ = 21289466512384.

The previous prime is 21312123111001. The next prime is 21312123111029. The reversal of 21312123111023 is 32011132121312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21312123111023 - 2³⁰ = 21311049369199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21312123111023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312123111029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111312911 + ... + 111504207.

It is an arithmetic number, because the mean of its divisors is an integer number (2666847540996).

Almost surely, 2^{21312123111023} is an apocalyptic number.

21312123111023 is a deficient number, since it is larger than the sum of its proper divisors (22657216945).

21312123111023 is a wasteful number, since it uses less digits than its factorization.

21312123111023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309153.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21312123111023 its reverse (32011132121312), we get a palindrome (53323255232335).

The spelling of 21312123111023 in words is "twenty-one trillion, three hundred twelve billion, one hundred twenty-three million, one hundred eleven thousand, twenty-three".